Re: what's cooking in zram for 4.1

[Karel Zak <kzak@redhat.com>]

On Sat, May 09, 2015 at 01:21:48PM +0900, Sergey Senozhatsky wrote:
> There will be some user-space visible changes in zram 4.1 we'd love to let you know
> about.

Thanks.

> 2) zram has deprecated some of the existing stat sysfs attributes. we will
> consolidate zramX device's stats in 3 files, rather than having N files (per-stat).

sysfs attributes used by zramctl(8) are:

    disksize
    orig_data_size
    compr_data_size
    comp_algorithm
    max_comp_streams
    mem_used_total
    reset

> -- /sys/block/zram<id>/mm_stat
> 
> The stat file represents device's mm statistics. It consists of a single
> line of text and contains the following stats separated by whitespace:

hmm... frankly, the reason why I love /sys and why hate /proc is
value-per-file. You do not need special parsers to read from /sys
(usually).

>         orig_data_size
>         compr_data_size
>         mem_used_total
>         mem_limit
>         mem_used_max
>         zero_pages
>         num_migrated

Why do you need all in one file? ... to provide consistent statistics?


    Karel


-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com